Not Much Again.............

Here's a current super novae I haven't mentioned this week.

Supernova 2011dh, which was discovered in the Whirlpool Galaxy, M51, on May 31st, has been brightening ever since — though the brightening is now levelling off. As of June 16th the supernova was about V magnitude 12.6 and visible in a lot more amateur telescopes. 

Well so much for last weeks eclipse, which wouldn’t have been overly fantastic even if it hadn’t been cloudy, which it obviously was, but never mind there’s another one on December the 10^th, but its at 2:30 in the after noon but we should catch the tail end of as the moon rises at about 4, with the sun setting shortly afterwards. Putting disappointing lunar eclipses to one side, which is always a little traumatic, this week, is much last week. But we do have an event coming up in less than a half hour, at 8:16 in fact, summer starts and the axis of the earth’s rotation starts to edge away from the sun. So today is the longest day, with about 16 hours of daylight. This gives me an excellent opportunity to waffle.

The Earths axial tilt is 23.4 degrees and it always points in the same direction throughout the year, which means it changes with respect to the sun. In spring and summer towards and in autumn and winter away from the sun. At the equinoxes the tilt is at right angles to the sun and we have equal days and nights. Now 23 and half degrees may not seem much but double it and it makes the sun 47 degrees higher today at noon than it will be in mid winter, which is a lot. Now you may have noticed that the rate of change of daylight hours is much slower now or in mid winter than it is in early spring or autumn. It’s best thought of as a pendulum effect, at 8:16 the days stop getting longer and begin to slowly get shorter. The pendulum has reached the top of its swing and starts to fall the other way and begins accelerating again down to the bottom of the swing, which next happens at the autumn equinox, when the swing begins to slow again toward the winter solstice when it will stop and then begin to fall toward mid summer again. And like any pendulum effect the swing is always faster at the bottom slowing to zero at the top.

Now because we had a full moon last week, we have a last quarter moon this week which will rise in the early hours and means that when the stars do come out form 11pm onwards they will be showing well, this of course is under the rather optimistic assumption that the skies ever clear, well if the do the milky way should be lovely arcing over head the North East to the South East, and there’s always the possibility of shooting stars, not that we are expecting a shower at the moment.

As for the planets bar Jupiter and Saturn they are all to close to the Jupiter at the Aries-Pisces border shines in the east during dawn, if you’re up and about it will just about the only thing of note in that part of the sky.

Saturn is in fine view in the south to southwest after dusk. And just ¼° to its upper right is fainter Porrima (Gamma Virginis), turning Saturn into a naked-eye "double star." Shining 15° to Saturn's left is Spica.

And that was your night’s sky for the week ending on the 120^th anniversary of The Street railway in Ottawa, Ontario, Canada, commencing operation.